Charge ordered state and giant magnetoresistance in Pr0.7R0.1Ca0.2MnO3 (R = Y, Dy, Gd, Sm, Nd)

The partial substitution of Pr by the rare earth elements (Y, Dy, Gd, Sm, Nd) in Pr0.8Ca0.2MnO3 induces charge ordering at 120 K. The insulator to metal transition associated with a large negative magnetoresistance has been observed in the presence of magnetic field. The metallic state is destroyed under application of magnetic field and returns to an insulating state at low temperature. The magnetoresistance reveals a broad maximum upon cooling from 150 to 100 K. These results are interpreted by double-exchange interaction and Jahn-Teller distortion. (author). Letter-to-the-editor